The engine immobiliser system is designed to prevent the vehicle from being stolen. This system uses a transponder key ecu that stores the key codes of authorized ignition keys. If an attempt is made to start the engine using an unauthorized key, the ecu sends a signal to the ecm to prohibit fuel delivery and ignition, effectively disabling the engine.

The transponder key coil receives this signal, the transponder key amplifier amplifies it, and then the signal is transmitted to the ecu. The ecu matches the key's id code with the vehicle's id code, which was previously registered in the ecu and then communicates the results to the ecm using sfi communication.
Engine immobiliser system
How to proceed with troubleshootingInstalling child restraints
Follow the child restraint system manufacturer’s instructions.
Firmly secure child restraints to the seats using the latch
anchors or a seat belt. Attach the top tether strap when installing
a child restraint.
The lap/shoulder belt can be used if your child restraint system
is not compati ...
Light bulbs
You may replace the following bulbs by yourself. The difficulty
level of replacement varies depending on the bulb. If necessary
bulb replacement seems difficult to perform, contact your
toyota dealer.
For more information about replacing other light bulbs, contact
your toyota dealer.
Prepari ...
Bleeding
Hint:
If any work is performed on the brake system or if air in the
brake lines is suspected, bleed air from the brake system.
Notice:
Wash off brake fluid immediately if it comes in contact
with any painted surface.
Remove cowl top ventilator louver bracket lh
Detach the 6 claws and ...